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Blended refuges for corn-expressing toxins from Bacillus thuringiensis (Bt) Berliner controls have been approved in the United States as an alternative resistance management approach to structured refuge. This study examined the impact of blended refuges up to 30% non-Bt seed on the corn earworm, Helicoverpa zea (Boddie) (Lepidoptera: Noctuidae), larval numbers, and kernel injury, and its effect on corn grain yield and test weights. The percentage of infested ears, larval numbers, and kernel injury of the 20% blend were not significantly different from the non-Bt and nonblended Bt for the Cry1A.105 + Cry2Ab + Cry1Fa2 treatment, but infested ears, larval numbers, and kernel injury of the nonblended Cry1A.105 + Cry2Ab treatment was lower than the comparable non-Bt hybrids, with the 20% blend being intermediate. The nonblended Cry1A.105 + Cry2Ab + Vip3Aa20 had virtually no larvae in ears and no kernel injury. Ear infestation, larval numbers, and kernel injury of the non-Bt blends with Vip3Aa20 were proportional to the percentage of non-Bt seed in the blend, and all infested ears were from the non-Bt refuge plants. Grain yield and test weight were not significantly different among nonblended or blended treatments of any Bt product tested. Results indicate losses of grain yield and test weight by corn earworm in seed blends up to 30% non-Bt seed are unlikely with infestation levels observed in this study. [ABSTRACT FROM AUTHOR]

Mid-forest meadows are integral to maintaining biodiversity and ecological services in forested landscapes but face degradation due to various reasons. This study evaluated the effectiveness of renovation methods on sward yield and herbage quality in two mid-forest meadows in northwestern Poland (54°10′ N, 16°78′ E), aiming to maintain their function as the foraging areas for the free-living red deer population. The results indicated that overdrilling was insufficient to significantly enhance sward quality or productivity (with no significant differences in DM yield between treatment and control), largely due to competition with existing vegetation and suboptimal habitat conditions. The full tillage method, in combination with sowing dedicated seed mixtures, substantially improved the sward yielding and forage quality, especially in terms of DM yield (av. 7% on object W; 18% on object TD). The efficacy of renovation methods varied between experimental sites, suggesting that the renovation strategy of mid-forest meadows should be tailored according to the habitat conditions.

Forests are degraded from various factors, and the first step in restoration frequently involves revegetation. One of the degradations is wildfires, which damage vegetation, affect soils, and lead to the loss of ecosystem functions. Using seed mixtures is a viable method for restoring the ecosystems. This research investigated the impacts of six perennial plant seed mixtures derived from native plants in South Korea and the addition of two types of annual plant seeds to these mixtures, both separately and combined. Cultivation of the seed mixtures was conducted by pot cultivation in a greenhouse for the early stage of vegetation (16 weeks). The seed mixture treatment enhanced plant species diversity, number, and biomass. The seed mixture treatment elevated the urease activity from 14.42 to values between 33.88 and 55.74 μg NH4-N g−1 2 h−1. A seed mixture integrated with two annual plants heightened the phosphomonoesterase activity from 482.79 to 543.75 μg p-nitrophenol g−1 h−1. Nitrogen leaching was reduced across all seed mixture treatments, while phosphorus leaching diminished with the addition of the annual legume. These findings illustrate the influence of seed mixture treatments and the inclusion of annual seeds on the beginning stage of revegetation, offering a basis for further ecosystem restoration. [ABSTRACT FROM AUTHOR]

In agroecosystems, species‐rich habitats, such as linear field margins and flower strips, are beneficial to the overall biodiversity and contribute to pest control. Their effects are thought to be mediated by plant species composition and diversity. However, the management of plant communities with targeted levels of functional diversity has been little investigated. In an open field landscape, we compared the effects of the sown species richness (9, 14, and 29 species) and functional diversity (high vs. low) of eight different seed mixtures, sown in flower strips, on the 4‐year temporal dynamics of their functional diversity. There was a good agreement between the expected and realized species richness and functional diversity at the start of the experiment. All plant assemblages progressively lost species over time, but this decline was lower for assemblages sown with a high initial functional diversity, in which species evenness was maintained at higher levels. Species‐rich assemblages had a higher degree of functional redundancy, and their functional diversity remained higher over time than less rich assemblages. A possible explanation for this is that functional redundancy would have enabled the compensation for the loss of species by functionally equivalent species. The realized functional diversity of the sown species also limited the establishment of spontaneous species, perhaps due to a higher degree of niche occupancy. This study provides useful insight into the creation of functionally diversified plant communities. A high level of initial species and functional diversity is required to guarantee a greater temporal persistence of the communities. [ABSTRACT FROM AUTHOR]

BACKGROUND: Seed mixture strategy can guarantee the compliance of planting non‐Bt crops to host the susceptible insects for resistance management. However, pollen movement between Bt and non‐Bt corn in the mixed plantings could reduce the efficacy of this strategy for ear‐feeding insects. Few studies have evaluated the effects of cross‐pollination among non‐Bt and pyramided Bt corn in seed mixtures on the resistance development of insects possessing multiple resistances. Here, we provided the first study to investigate whether cross‐pollination in mixed plantings of pyramided Bt corn producing Cry1A.105 and Cry2Ab2 would increase the dominance of resistance of dual‐gene resistant populations of Helicoverpa zea, a target of pyramided Bt corn and cotton in the USA. RESULTS: We compared the survival and development of susceptible, dual‐gene resistant (resistance to both Cry1 and Cry2 proteins) and heterozygous genotypes of H. zea in the laboratory on non‐Bt and pyramided Bt corn ears collected from mixed plantings and structured plantings in the field. We found higher fitness for F1 heterozygous insects than for the susceptible insects of H. zea on both pyramided Bt corn and non‐Bt corn in the mixed plantings. CONCLUSION: These results suggest that cross‐pollination in mixed plantings will significantly increase the dominance of resistance by supporting survival of heterozygous insects for dual‐gene resistant populations of H. zea, and therefore accelerate evolution of resistance to pyramided Bt crops. © 2022 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Safflower (Carthamus tinctorius L.) is an important source of edible oil and bioenergy with its high quality oil in its seeds. In this research, seed mixtures were made in advanced generation safflower lines to benefit from both the natural heterosis effect and the advantages of multi-line varieties. Three safflower lines (BAY-ER 2, BAY-ER 5 and BAY-ER 15) with similar phenological characteristics, but different seed and oil yields were used. Pure, double (1/2 + 1/2) and triple (1/3 + 1/3 + 1/3) seed mixture ratios were grown under open pollination condition. The partial hybrid seeds were planted in randomized block experimental design with three replicates in the following year to evaluate the the agricultural and quality characteristics. Statistically significant differences were found between pure lines and mixtures in terms of plant height, number of branches, number of heads, 1000 grain weight, seed hull ratio, oil ratio, seed yield and oil yield. Double and triple seed mixtures showed higher yield performance than pure lines, and high mixing efficiency was obtained as 50.7% from BAY-ER 2 + BAYER 15 and 44.0% from BAY-ER 5+ BAY-ER 15 binary mixtures. All the mixtures gave higher seed yield and oil ratio than their pure lines. Linoleic acid ratios in the lines and oleic acid ratios in the mixtures were found to be slightly higher. As a result, it has been understood that agricultural performance can be increased with different ratios of seed mixtures of a certain number of pure lines in safflower. [ABSTRACT FROM AUTHOR]

Farmland bird populations are in a deep crisis across Europe. Agri-environment schemes (AES) were implemented by the European Union to stop and reverse the general decline of biodiversity in agricultural landscapes. In Germany, flower strips are one of the most common AES. Establishing high-quality perennial wildflower strips (WFS) with species-rich native forb mixtures from regional seed propagation is a recent approach, for which the effectiveness for birds has not yet been sufficiently studied. We surveyed breeding birds and vegetation on 40 arable fields with WFS (20 with single and 20 with aggregated WFS) and 20 arable fields lacking WFS as controls across Saxony-Anhalt (Germany). Additionally, vegetation composition, WFS quantity and landscape structure (e.g. distance to nearest woody element) were considered in our analyses. All WFS were established with species-rich native seed mixtures (30 forbs) in agricultural practice as AES. Arable fields with WFS had a higher species richness and territory density of birds than controls, confirming the effectiveness of this AES. A forb-rich vegetation was the main driver promoting birds. Flower strip quantity at the landscape level had positive effects only on bird densities, but also single WFS achieved benefits. A short distance from WFS to woody elements increased total bird species richness. However, the density of farmland birds, which are target species of these AES, were negatively affected by the proximity and proportion of woody elements in the vicinity. The effect of the proportion of non-intensively used open habitats and overall habitat richness was unexpectedly low in the otherwise intensively farmed landscape. Species-rich perennial WFS significantly promoted breeding birds. Successful establishment of WFS, resulting in high-quality habitats, a high flower strip quantity as well as implementation in open landscapes were shown to maximise the effectiveness for restoring declining and AES target farmland birds. [Display omitted] [ABSTRACT FROM AUTHOR]

The process of obtaining high-quality tobacco seeds is very laborious, and at present many operations are performed manually at All-Russian Research Institute of Tobacco, Makhorka and Tobacco Products. The process of obtaining tobacco seeds at the Institute consists of the following operations: harvesting of inflorescences, drying of inflorescences, destruction of inflorescences, screening out coarse impurities, final cleaning in an air stream. An attempt was made earlier to mechanize and improve working conditions at the stage of final purification of the seed mixture. A unit for the final purification of tobacco seeds was developed, manufactured and tested. In this article other modes of final purification of the tobacco seed mixture to improve mechanization and productivity of the same unit have been tested. The seed mix of the 2019 harvest has been used in the studies. Coarse impurities have been separated from the seed mix by sieving through sieves with different hole sizes. Earlier modes of double final purification of seed mixture were proposed. In this research the previously proposed double cleaning modes have been taken as control ones, and in the experiment three-fold modes with a higher feed rate of the seed mixture have been used. As a result, the experimental modes provide identical removal of contaminants, however, the productivity of the unit increases 2 – 3 times due to the shorter total duration of purification, and mechanization is also improved due to a more uniform flow of the seed mixture. In this case, there is no need for the constant presence of an operator, and the process of final purification of the tobacco seed mixture is reduced only to its loading and unloading.

Sowing of grass seed mixtures is a feasible and cost‐effective method for landscape‐scale grassland restoration. However, sowing only grasses usually leads to species‐poor and dense swards, where the establishment of target forbs is hampered by microsite and propagule limitation. To overcome these limitations and increase the diversity of species‐poor sown grasslands, we developed a novel method by creating "establishment gaps.". We used tillage to open gaps of 1‐, 4‐, and 16‐m2 size in the dense grass sward of six species‐poor restored grasslands in the Great Hungarian Plain. We sowed high‐diversity seed mixtures of 35 native species into all gaps. We analyzed vegetation development during the first 5 years after setting up the trial. We also studied the colonization dynamics of the sown species along four 20‐m transects around each gap, resulting in a total of 1440 plots of 1‐m2 size that were studied. Our results indicated that most of the sown species were able to establish permanently in the gaps. The total cover and the cover of perennial sown species increased and the cover of short‐lived sown species decreased independent of gap size. There was only a moderate level of weed abundance in the gaps, and weed cover decreased over the years. The sown target species started to colonize the species‐poor grasslands surrounding the gaps within 5 years. The highest number of species and individuals dispersed from the 4‐m2 gaps, as they had a more stable development than smaller gaps and were exposed to lower grazing pressure than large ones. [ABSTRACT FROM AUTHOR]

Restoration of riverbanks through soil bioengineering techniques allows managers to combine riverbank stability and riparian ecosystem functioning. This restoration often involves the sowing of a seed mixture, which helps develop herbaceous vegetation. This development and sufficient vegetation cover are essential for protection against erosion and for hosting biodiversity, two of the main goals of riverbank bioengineering. Restoration aims at recreating ecosystems closer to an undisturbed state; choosing seed mixtures of local provenance is therefore encouraged. In this study, we investigated the local seed mixture sown on bioengineered riverbanks and the conditions influencing the first steps of plant development, so as to delineate the setting favoring restoration. We focused on the composition of the seed mixture and germination capacity as well as the effect of sowing density and soil quality on vegetation cover and diversity. We tested four sowing densities: 5, 10, 15, and 30 g.m−1. The seed mixture presented considerable diversity and germination rates were heterogeneous. Sowing density had a positive impact on vegetation cover and diversity, and high cover up to 100% was rapidly reached. Soil quality did not affect vegetation diversity but had a significant effect on vegetation cover, with the nutrient content, notably nitrogen, most probably involved. [ABSTRACT FROM AUTHOR]

Forage kochia (Bassia prostrata L.) can persist in disturbed areas and provide high‐quality forage even during fall and winter months. However, information is needed on the effect of planting time and subsequent environmental conditions on forage kochia establishment. A field study was initiated in 2014 in Wyoming to determine the optimum planting time for successful forage kochia establishment and examine its performance in seeded mixtures with perennial cool‐season grasses in areas dominated by annual weeds. The experiment was carried out using split‐plot in a randomized complete block design with four replications. The main plots consisted of three planting times (late winter, early spring and summer), and subplots included eight seeding mixture treatments. Species included in mixtures were forage kochia, four native grasses and two nonnative grasses. The summer (May) planting failed completely, and early spring (April) planting resulted in greater plant density for forage kochia and grasses than late winter (March) planting. Although, forage kochia monoculture had greater forage kochia density than other treatments, forage kochia stands were satisfactory when seeded in mixtures with perennial grasses. By the year after planting, plant density of forage kochia and grasses was reduced to about one‐third of 2014 density. During initial establishment stage, it is thought that forage kochia and perennial grasses were affected by dense cover of annual weeds. However, greater plant density was observed for April compared to March plantings, and forage kochia monoculture had good stands despite dense stands of annual weeds, even in 2015. The results suggest that successful establishment of forage kochia is possible when it is planted in early spring under conditions of this study. However, monitoring stands the following years is needed to determine the persistence and forage production of different seeding mixtures of forage kochia and perennial grasses. [ABSTRACT FROM AUTHOR]

One of the main questions in ecosystem restoration is where to obtain the seeds to re-establish plant communities. While the most commonly advocated approach is to use seeds from local sources, some experts argue against this because local populations may harbour little genetic variability for the restored populations to be able to adapt to and survive global change. Instead, they propose alternative strategies such as mixing seeds from various sources to increase genetic variability and adaptive potential, or using seeds from populations that have a similar climate as predicted for the target locality in the future. All these alternative seed-sourcing strategies have in common that they involve a transplanting of plant ecotypes, sometimes over large spatial scales. This is risky because plants from distant origins may be maladapted to the current local abiotic and biotic environment. In addition, introduction of non-local provenances will disrupt natural patterns of within-species biodiversity and will affect ecological networks, with unpredictable consequences. To balance the value of local adaptation with the need for future adaptation potential, we propose 'regional admixture provenancing' as a compromise strategy. Here seeds are sourced from multiple populations within the same region as the target locality and mixed prior to use. The mixing of seeds will increase the genetic diversity necessary for future adaptation, while restricting seed origins to a regional scale will maintain regional adaptation and reduce the risk of unintended effects on other biota. This approach is feasible in practice and has recently been implemented in Germany. We believe that it represents a compromise to reconcile opposing views on ecological restoration. [ABSTRACT FROM AUTHOR]

Mountain environments play a crucial role in maintaining biodiversity despite becoming more vulnerable to colluvial processes primarily induced by extreme meteorological events. Soil bioengineering stabilizes mountain slopes and limits impacts on ecosystems and is increasingly used worldwide, yet its effectiveness requires better assessment through post-intervention environmental monitoring. However such studies are only rarely performed even though they are essential to improve future intervention. This study reports soil and vegetation monitoring data of an area in the Italian Alps in which soil bioengineering work was carried out to restore an area hit by landslides. The monitoring involved an analysis of the floristic-vegetational and ecological features of the plant communities of the area of the soil bioengineering intervention (and in adjacent areas), as well as an analysis of the chemical-physical characteristics of the soils (texture, pH, organic matter, nitrogen content, roots depth) where these communities were established. The results of the monitoring, analyzed in the overall framework of the state of the art of the sector, have highlighted some lines of research and action that should be undertaken by technicians, researchers, and politicians to innovate and to make work aimed at the stabilization of landslides more effective. In particular, it would be extremely useful to study the biotechnical characteristics of herbaceous plants that are still "unknown" in soil bioengineering and to evaluate their possible effects on ecosystems in order to produce seed mixtures that, besides being useful for soil stabilization, can accelerate vegetation dynamics, therefore maximizing the success of such works. [ABSTRACT FROM AUTHOR]

In this review, we evaluate the intentional mixing or blending of insecticidal seed with refuge seed for managing resistance by insects to insecticidal corn (Zea mays). We first describe the pest biology and farming practices that will contribute to weighing trade-offs between using block refuges and blended refuges. Case studies are presented to demonstrate how the trade-offs will differ in different systems. We compare biological aspects of several abstract models to guide the reader through the history of modeling, which has played a key role in the promotion or denigration of blending in various scientific debates about insect resistance management for insecticidal crops. We conclude that the use of blended refuge should be considered on a case-by-case basis after evaluation of insect biology, environment, and farmer behavior. For Diabrotica virgifera virgifera, Ostrinia nubilalis, and Helicoverpa zea in the United States, blended refuge provides similar, if not longer, delays in the evolution of resistance compared to separate block refuges. [ABSTRACT FROM AUTHOR]

BACKGROUND Seed mixture, also called 'RIB', has been used to provide refuge populations for delaying insect resistance. Pollen contamination in RIB could result in refuge kernels of non-Bt maize expressing variable Bt proteins. Data are lacking regarding the impact of pollen contamination on evolution of resistance for ear-feeding insects. Here, we used Spodoptera frugiperda and Cry1F-maize as a model to examine if pollen contamination in RIB increases the dominance of insect resistance. RESULTS Pollen contamination caused >66% refuge kernels in 5:95% (non-Bt:Bt) and 20:80% RIBs to express Cry1F protein. Survival at adult stage on pure non-Bt ears was similar (54.4-63.3%) among Cry1F-susceptible (SS), Cry1F-resistant (RR) and Cry1F-heterozygous (RS) S. frugiperda. On Bt ears, survival was similar between SS and RS (0.0-1.7%), but it was significantly less than that of RR (59.2%). On the two RIB refuge ears, survival at adult stage for RS (42.3% in 5:95% RIB; 50.0% in 20:80% RIB) was significantly higher than for SS (8.7% in 5:95% RIB; 10.0% in 20:80% RIB). CONCLUSION The results suggest that pollen contamination in RIB could increase the dominance of resistance for ear-feeding insects by significantly reducing susceptible refuge populations and supporting higher survival of heterozygotes relative to homozygous susceptible insects. © 2017 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

This 6-year experiment quantified the impacts of management factors on red clover yield, persistence, nutritive value and ensilability, and compared these with perennial ryegrass receiving inorganic N fertilizer. Within a randomized complete block design, field plots were used to evaluate a 2 (cultivar, Merviot and Ruttinova) × 2 (alone and with perennial ryegrass) × 2 (0 and 50 kg fertilizer N ha−1 in mid-March) × 2 (harvest schedule) combination of the factors relating to red clover, and a 2 (harvest schedule) × 4 (0, 50, 100 and 150 kg N ha−1 for each cut) combination of the factors relating to perennial ryegrass. The early and late harvest schedules both involved four cuts per year, but commenced a fortnight apart. Red clover treatments averaged 14 906 kg dry matter ( DM) ha−1 per year, whereas perennial ryegrass receiving 600 kg inorganic N fertilizer per year averaged 14 803 kg DM ha−1 per year. There was no yield decline evident across years despite a decline in the proportion of red clover. The early harvest schedule and sowing ryegrass with red clover increased the herbage yield and digestibility. March application of fertilizer N to red clover treatments reduced the annual yield. Early harvest schedule increased and both fertilizer N and sowing with ryegrass decreased the proportion of red clover. Sowing with ryegrass improved the indices of ensilability, but reduced the crude protein content. Both red clover cultivars had similar performance characteristics. A selected red clover-based treatment, considered to exhibit superior overall production characteristics, outyielded N-fertilized perennial ryegrass in mid-season. However, it had poorer digestibility and ensilability indices. [ABSTRACT FROM AUTHOR]

Questions (1) When alpine vegetation is actively restored by seeding, how is vegetation cover influenced by seeding treatments and soil conditions? (2) How does the cover of species differ when they are seeded in a mixture and how is their response influenced by soil conditions? (3) Do individual species perform better or worse in a mixture than when sown separately? Location Hjerkinn, Dovrefjell, Norway. Methods In a factorial, randomized field experiment, we recorded the percentage cover of Festuca ovina, Luzula multiflora subsp. frigida and Poa alpina seeded in four different soil types for 3 yr after seeding. We seeded the three species separately and in a mixture in organic topsoil, peat soil, mineral fine soil and mineral coarse soil. We also recorded seedling emergence in a greenhouse experiment, using the same seeding treatments. Results In the field experiment, vegetation cover established fastest when F. ovina was sown in monoculture, followed by the seed mixture. After 3 yr, mean cover of F. ovina was 1.4 times higher than mean P. alpina cover and more than three times higher than mean L. multiflora cover for single species treatments, and four ( P. alpina) and 15 ( L. multiflora) times higher when the species were seeded together. L. multiflora germinated slowly in the greenhouse experiment, which could partly explain its poor field performance. In the field experiment, establishment was faster in organic soils than mineral soils for all seeding treatments. The largest difference between F. ovina and L. multiflora performance in the mixture treatment was found in the organic soil types, where overall cover was larger than in the mineral soils. In the organic soils, F. ovina was slightly facilitated in the mixture treatment, while the opposite was found for L. multiflora. Conclusion When the restoration goal is to quickly establish a vegetation cover, seeding monocultures of rapidly establishing species may be more effective than seeding mixtures, even in alpine sites, where interspecific facilitation may prevail. [ABSTRACT FROM AUTHOR]

Revegetation is the most sustainable method of soil stabilization at ski runs. In order to establish a stable plant community, it is recommended to use native species. However, non-native species are most often used. In this paper the revegetation of ski runs at two ski resorts is investigated: Divčibare and Stara Planina. Seven species were used for the revegetation of the ski run at the Divčibare ski resort of which six species were native. Six species were used for the revegetation of the Stara Planina ski resort, of which two species were native. It was established that the plant species used in the seed mixtures were suitable for erosion control at the investigated ski resorts.

Flower strips are a commonly used tool for improving agricultural landscapes for pollinators. The plant composition of the seed mixtures employed is based on logistic decisions, e.g. costs or seed availability, the literature and expert opinion, and only rarely on direct information about bee-plant interactions. We combined two datasets on bee-plant interactions involving 460 bee species. The first consisted of 23,864 bee-plant interactions, recorded in twenty locations in Germany from 2018 and 2019, whereas the second consisted of 86,509 bee-plant interactions sampled across multiple sites in southwest Germany over more than 30 years. We explored three objectives. (1) Which plant species attract the greatest number of wild bee species and individuals across plant communities within and across seasons of bee activity? (2) Do the most attractive plant species also support threatened and specialized wild bees? (3) Do seed mixtures contain attractive plant species? High attractiveness was defined as a consistently high interaction frequency and number of visiting bee species to a plant species across the sampled communities. Our results identified 34 herbaceous key plant species that were highly attractive for wild bees independently of plant abundance and across locations. Further, we identified a large number of plant species for which the attractiveness for wild bees depended on the sampled community. The identified key plant species attracted between 2% and 32% of oligolectic or red-listed bees present in our datasets. Although some of these plant species, such as Centaurea cyanus or C. jacea , are commonly found in seed mixtures, others, such as Stachys recta or Carduus nutans , are not. These large-scale and robust interaction data highlight key plant species that provide an attractive core for herbaceous floral strips aimed at supporting high numbers of wild bee species. [Display omitted] • Key plants support high numbers of wild bee species. • Attractive core for seed mixtures in agri-environmental schemes. • Comprehensive dataset with 100,000 bee-flower interactions. • Recommendations for oligolectic (flower specialist) and red-list bee species. [ABSTRACT FROM AUTHOR]

Fall armyworm (FAW), Spodoptera frugiperda (J. E. Smith), is the main target pest of transgenic maize expressing insecticidal proteins from Bacillus thuringiensis Berliner (Bt) in Brazil. To optimize resistance management strategies, we evaluated the functional dominance of different aged larvae of Bt-resistant FAW on Vip3Aa20 maize. We measured the survival and development of Vip3Aa20-resistant, -heterozygote, and -susceptible strains on MIR162 (expressing Vip3Aa20) and Bt11 × MIR162 × GA21 (expressing Vip3Aa20 and Cry1Ab) maize. The resistant strain, from neonate to sixth instar, showed more than 72% survival on Vip3Aa20 maize. From surviving larvae, more than 64 and 54% developed to pupae and adults, respectively. In contrast, heterozygote and susceptible strains showed no larval survival up to fourth instar, and less than 25% larval survival in the fifth and sixth instar on Vip3Aa20 maize. These larvae produced less than 21% of pupae and adults. The development time of FAW strains from neonate-to-adult exposed to Vip3Aa20 maize was similar; however, the resistant strain showed an increase of ∼ 2 d when compared to those fed only non-Bt maize. In summary, the resistance of S. frugiperda to Vip3Aa20 maize is functionally recessive from neonate up to fourth instar larvae. However, high larval survival of resistant strain and some survival of heterozygote larvae in advanced instars on Vip3Aa20 maize were observed. These results will be important for designing insect resistance management to Bt maize plants expressing Vip3Aa20 protein in Brazil. [ABSTRACT FROM AUTHOR]

Insect resistance management for Bt traits in corn has recently moved toward refuge-in-the-bag, which consists of simple cultivar mixtures of susceptible and resistant hybrids. The purpose of these seed mixtures has thus far been solely to maintain susceptible pest insects, which will help prevent the development of resistance and preserve utility of the technology. It appears that this narrow focus on resistance management overlooks broader production benefits that may be achieved by planting genotypically diverse cultivar mixtures. While not yet widely employed in modern agriculture, cultivar mixtures have been successfully used for disease management, demonstrating that the strategy is logistically feasible for intensified agriculture. Evidence from both natural and agricultural systems demonstrates that more genotypically diverse plantings can increase yield or productivity through a variety of mechanisms. These effects are in part attributable to improved response to both abiotic and biotic stressors, such as drought, temperature stress, competitors, herbivores, and disease. Similar to transgenic traits, cultivar mixtures also hold promise for resistance management for traditionally bred, or native, traits. [ABSTRACT FROM AUTHOR]

Copyright of Basic & Applied Ecology is the property of Urban & Fischer Verlag and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Scientific Journal of National University of Life & Environmental Sciences of Ukraine. Series: Technique & Energy of APK is the property of National University of Life & Environmental Sciences of Ukraine and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The paper explains, on the basis of the minimum power principle, the phenomenon of layering a mixture of material particles (especially seeds of cereals) maintained under an oscillating motion, with or without the action of an air stream. This phenomenon of separation into fractions is also generalized on a mass of particles with the same specific weight, but with different sizes, an untreated aspect, in this form, in the specific literature. [ABSTRACT FROM AUTHOR]

Annual plant species have great potential on green roofs as many are highly attractive, fast and cheap to establish via sowing and can provide rapid cover and growth, which is important for ecosystem service provision. While irrigation is essential for survival and growth of annual plants in seasonally hot or dry climates, it is also important to minimize water use as availability is often limited. Therefore, we evaluated how irrigation frequency affects plant cover, species abundance, richness and diversity, plant traits and functional diversity of a 16 species mixture of Australian annual species (4 g m−2 ~ 2100 seeds m−2) sown onto thirty 0.25 m2 green roof modules. The experiment was carried out in Melbourne, Australia, from January (summer) to July (winter) 2020. After a 2-month irrigated establishment phase (to ensure germination and seedling establishment), three irrigation treatments (2, 4 and 6 days between irrigation) were applied to the modules for three months. Plant cover was reduced at lower irrigation frequency (6 days), but ≥ 80% plant cover was achieved in all irrigation treatments. There was no effect of irrigation frequency on species abundance and richness; however, abundance, richness and diversity reduced over time, likely due to competition effects. Plant height and leaf area were also reduced by lower irrigation frequency. At the community level, functional diversity was unaffected by irrigation frequency. Our results indicate that green roofs sown with a mixture of annual plants can achieve good plant coverage, as recommended by green roof guidelines, and maintain high diversity when minimally irrigated in their first growing season. [Display omitted] • We investigated how irrigation frequency affects annual plant mixture on green roof. • All modules sown with annual species achieved > 80% plant coverage after 5 months. • Species abundance and diversity reduced over time, likely due to competition. • Functional diversity was same between highest and lowest irrigation frequency. • Annual plant mix has high potential to grow on extensive roofs with low irrigation. [ABSTRACT FROM AUTHOR]

Sendžikaitė J., Pakalnis R., Gudžinskas Z., 2013: Changes in botanical diversity of sown grasslands due to naturalization and extensive management [Sėtų pievų botaninės įvairovės kaitos dėl žolynų natūralėjimo ir ekstensyvaus naudojimo]. - Bot. Lith., 19(2): 99-110 The paper deals with sown grassland naturalization models related to changes in botanical diversity of extensively managed meadows under temperate climate conditions. The vegetation surveys were carried out in Sėliškės and Polyma Experimental Field Stations (Lithuania). Based on our research data and literature sources (on the investigation of Lithuanian natural meadows), we developed the following hypothetical models of sown grassland naturalization: vascular plant species constancy alteration chronocline, vascular plant species constancy and productivity alteration topocline and a scheme of sown grassland naturalization on hilly landscape. Here we consider extensive management and naturalization as one of most natural and requiring minor investments method for grassland restoration. [ABSTRACT FROM AUTHOR]

Abstract: This study investigated the establishment of annual meadow including native and non-native species in an extensive green roof in Sheffield, UK. The study aimed to determine the feasibility of establishing annual plant species from a seed mixture and to determine the appropriate sowing rate as well as the necessity of watering during the first growing season from June to November 2006. A 22-species seed mixture was sown on an experimental green roof with a substrate depth of 7cm using two sowing rates (2g/m2 and 4g/m2) and two watering regimes (with and without watering). The watering regime consisted of application of water four times over the course of the experiment. Each combination of sowing and watering regime yielded a successful aesthetic annual meadow green roof. Results showed that a low sowing rate resulted in better conditions for individual plant growth when enough water was available. On the other hand, a high sowing rate was necessary to ensure a sufficient number of plants when water resources were not abundant. The watering regime improved growth in most species; however, it was determined that an annual seed mixture could perform well without watering at the study site. The annual meadow possessed an abundance of flowering plants for an extended period of time; plants started flowering one month after sowing and continued until the end of October. Successful species during the first growing season included Alyssum maritimum, Echium plantagineum ‘Blue Bedder’, Gypsophila muralis, Iberis amara, Iberis umbellata ‘Fairy’, Linaria elegans and Linaria maroccana. [Copyright &y& Elsevier]

This investigation was conducted to compare Poa and Cynodon turfgrasses and their seed mixtures. In this research the turfgrasses Kentucky bluegrass (Poa pratensis L. 'Merion') and common bermudagrass (Cynodon dactylon [L.] Pers.), in monoculture or in mixtures of 0 to 100%, based on number of seeds, were used. Perennial ryegrass (Lolium perenne L. 'Barball') (L) was used as control. The seeds were sown in October in 2005 and 2006 in southwest Iran with a dry and moderate climate. The experiment was conducted in a split-plot design with year as main plot and turfgrass types as subplot. The cultures were maintained as lawns and were mowed from 3 cm above the ground. The turfgrasses were compared by measuring visual quality after winter and summer, chlorophyll index after winter and summer, rooting depth, verdure and root fresh weight, tiller density, and clippings fresh weight. Poa monoculture had high tiller density, root fresh weight and total fresh weight. Lolium monoculture had high rooting depth after winter and clippings fresh weight. Cynodon monoculture quality was poor with regard to many characters, mainly due to fall sowing. The seed mixture composed of 40% Cynodon+60% Poa was the best treatment and resulted in the highest verdure fresh weight, chlorophyll index after winter and summer, visual quality after winter and summer, and established a good turf according to the other characters. This mixture can be used as an alternative in overseeding programmes in areas with soil and environmental conditions similar to the present research site. [ABSTRACT FROM AUTHOR]

Abstract: European Union (EU) member states set aside between 5 and 15% of arable land during the last two decades, but abolition of the set-aside scheme in 2008 caused a sudden loss in habitat availability and biodiversity in agricultural landscapes. Management of set-aside has many facets and in this perspective paper we focus on the biodiversity effects of successional age, sowing strategies and landscape context. Young, 1–2-year-old set-asides have been initially considered to be too ephemeral to have any conservation value. However, when a rich seed and bud bank is available, a species-rich natural (secondary) succession can be observed. Arable (annual) weed communities in the first two years of succession can even include endangered plant species with associated rare insect consumers. Furthermore, many bird species benefit from early-successional habitats, whereas small mammal communities are richer in older habitats. If the local plant species pool is poor, sowings of diverse mixtures from regional seed collections can be recommended. Set-aside managers using species-rich sowings often experience that dominant weeds suppress the less competitive annual species. This trend to species-poor communities can be avoided by intraspecific aggregation of competitively weak species. Broadening the spatial scale from the plot to the landscape, efficiency of set-aside is highest in simple landscapes, where set-aside exhibits greatest effect in enhancement of biodiversity and associated services such as pollination and biological control. In complex landscapes, however, additional set-aside does not add much to the high level of biodiversity and ecological processes already present. Twenty percent of semi-natural, non-crop habitat appears to be a rough threshold for enhancing biodiversity and sustaining services such as pollination and biological control, but improved set-aside management should have the potential to reduce the percentage of semi-natural non-crop habitat needed. EU policy should tailor set-aside schemes for the maintenance of biodiversity and also consider that management efficiency is higher in simple than complex landscapes. [Copyright &y& Elsevier]

A simulation model of the temporal and spatial dynamics and population genetics of western corn rootworm, Diabrotica virgifera virgifera LeConte, was created to evaluate the use of block refuges and seed blends in the management of resistance to transgenic insecticidal corn (Zea mays L.). This Bt corn expresses one transgenic corn event, DAS-59122-7, that produces a binary insecticidal protein toxin (Cry34Ab1/Cry35Ab1) and provides host-plant resistance. The model incorporates the latest information about larval and adult behavior. Results of this modeling effort indicate that the seed-blend scenarios in many cases produced equal or greater durability than block refuges that were relocated each year. Resistance evolved in the most likely scenarios in 10-16 yr. Our standard analysis presumed complete adoption of 59122 corn by all farmers in our hypothetical region, no crop rotation, and 100% compliance with Insect Resistant Management (IRM) regulations. As compliance levels declined, resistance evolved faster when block refuges were deployed. Seed treatments that killed the pest when applied to all seeds in a seed blend or just to seeds in Bt corn blocks delayed evolution of resistance. Greater control of the pest population by the seed treatment facilitated longer durability of the transgenic trait. Therefore, data support the concept that pyramiding a transgenic insecticidal trait with a highly efficacious insecticidal seed treatment can delay evolution of resistance. [ABSTRACT FROM AUTHOR]